Chapter 22: Disorders Of Hemostasis Flashcards
What is hemostasis?
The body’s way to maintain a certain level of existence
What is the inappropriate formation of clots within the vascular system?
Thrombosis
What is the failure of blood to clot in response to appropriate stimulus?
Bleeding
What are the factors that cause Hemostasis ( Blood Clotting)?
- infection, tissue damage, and healing
The process of hemostasis can be divided into how many stages?
Two
What prevents a client from bleeding to death?
Vascular Constriction
Which stage of hemostasis has platelet plug formation?
Primary Hemostasis
What happens in Vasoconstriction?
The walls of the blood vessels shrink to reduce the area that blood can flow through.
Which stage of hemostasis does vasoconstriction happen?
Primary Hemostasis
At which stage of hemostasis does the coagulation cascade happen?
Secondary Hemostasis
Hemo means what?
blood
Stasis means what?
Standing
Anticoagulants do what?
Keep blood from clotting
What process prevents the client from hemmorage ( bleeding to death) ?
Vascular constriction
What is blood coagulation?
A process where fibrin forms a chainlike net or mesh network
What type of cells become trapped in the network in blood coagulation?
Red and White Blood Cells
Which Coagulation Cascade is Intrisnic?
The PTT Pathway
What is clot retraction?
A process where serum is squeezed from the clot and edges of the vessel are pulled together
How long does clot retraction take?
20-60 minutes
Which Coagulation Cascade is Extrinsic and Faster?
The PT Pathway
What is clot dissolution?
This allows blood flow to be reestablished and permanent tissue repair
What is fibrinolysis?
A process where the clot is dissolved
What is hypercoagulability?
Increase the risk of clot or thrombus formation in the arterial or venous circulations
What factors are shared and required for both PTT and PT?
Factors V(5) and X(10)
Hypercoagulability due to increased platelet function results in what?
Platelet adhesion, formation of platelet clots and disruption of blood flow
What is the most important enzyme on the planet?
Thrombin
What is Factor Xa?
Prothrombin
Factor Xa( Prothrombin) converts into what?
Thrombin
What converts Fibrinogen into a solid Frbrin Clot?
Thrombin
T/F:
Without thrombin you can not form a clot.
True
What are the causes of increased platelet function?
disturbances in flow, endothelial damage, and increased sensitivity of platelets to factors that cause adhesiveness and aggregation.
What are the causes of increased platelet function?
disturbances in flow, endothelial damage, and increased sensitivity of platelets to factors that cause adhesiveness and aggregation.
What factor activates factor X(10) in the PT Pathway?
Factor 7
What is arterial thrombi?
Associated with conditions that produce turbulent blood flow and platelet adherence
What is venous thrombi?
Associated with conditions that cause stasis of blood flow with increased concentrations of coagulation factors
What conditions create increased platelet function?
-Atherosclerosis
-Diabetes mellitus
-Smoking
-Elevated blood lipoid and cholesterol levels
-Increased platelet levels
What factors are included in the PTT Pathway?
Factor(s): XII(12), XI(11), IX(9), VIII(8), and X(10)
What are conditions that cause accelerated activating of the coagulation system?
-Pregnancy and the 6-week period following childbirth
-Use of oral contraceptives
-Postsurgical state
- Immobility
-Congestive heart failure
-Malignant diseases
T/F:
If factor V(5) or X(10) are damaged both the PT and PTT pathway will not clot; resulting in continuous bleeding?
True
T/F:
Deficiency for Factor VII(7) will prolong the PT but not the PTT
True
What happens to a patient with thrombocytopenia? (low platelets)
They are at an increased risk of bleeding
T/F:
Deficiencies of Factor(s) XII (12), XI(11), IX(9), and VIII(8) will prolong the PTT But not the PT
True
What causes thrombocytopenia?
decrease in platelet production, increased sequestration of platelets in the spleen, or decreased platelet survival
What matters clinically about factor XII(12).
When deficient, other blood clotting factors compensate for its absence.
Drug-induced thrombocytopenia
(ASA, atorvastatin, antibiotics)
What causes Bleeding?
- Decrease in the number of circulating platelets
- Impaired Platelet Function
Idiopathic thrombocytopenic purpura (ITP)
platelet antibody formation and destruction of platelets
Thrombotic thrombocytopenic purpura
A lack of activity in the ADAMTS13 enzyme (a type of protein in the blood) causes overactive clotting)
In the decreasing number of circulating platelets what must be relatively sever before hemorrhagic tendencies of spontaneous bleeding occur?
- Depletion of platelets
What are some manifestations of thrombosis?
Bleeding in mucous membranes
-Nose
-Mouth
-Gastrointestinal tract
-Uterine Cavity
What is bleeding resulting from platelet deficiency and commonly occurs in small vessels? Often characterized by petechiae and purpura.
Impaired platelet function
Where does thrombosis occur?
small vessels
What is petechiae?
pinpoint purplish-red spots
(Seen almost exclusively in conditions of platelet deficiency)
What is an essential cofactor for synthesis of clotting factors ?
Vitamin K
Purpura
purple areas of bruising
What occurs in Vitamin K deficiency?
- Th liver produces inactive clotting factors resulting in abnormal bleeding.
What vitamin is Fat-solvable and is synthesized by intestinal bacteria ( or food source)?
Vitamin K
What causes coagulant deficiencies to arise?
defective synthesis, inherited disease, or increased consumption of the clotting factors
What causes coagulant deficiencies to arise?
defective synthesis, inherited disease, or increased consumption of the clotting factors
What is Disseminated Intravascular Coagulation (DIC)?
Acquired bleeding disorder, an alteration in the blood clotting mechanism: abnormal acceleration of the coagulation cascade which results in thrombosis; hemorrhage occurs simultaneously.
What are the Vascular disorders that cause bleeding?
- Hemorrhagic Telangiectasia
- Vitamin C Deficiency ( Scurvy)
- Cushing Disease
- Senile Ursula ( Bruising in Elderly Persons)
An uncommon autosomal dominant disorder Characterized by thin-walled, dilated capillaries and arterioles is known as what?
Hemorrhagic Telangiectasia
What disease causes protein wasting and loss of vessel tissue support due to excess cortisol?
Cushing Disease
What is the treatment for Disseminated Intravascular Coagulation (DIC)?
To manage primary disease
What is caused by the Aging Process?
Senile Purpura ( bruising in elderly persons)
What results in poor collagen synthesis and failure of the endothelial cells to be centered together properly, causing a fragile wall?
Vitamin C deficiency ( Scurvy )
What are some conditions associated with Disseminated Intravascular Coagulation (DIC)?
- Obstetric conditions
- Cancers
- Infections
- Shock
- Trauma or surgery
- Hematologic conditions